Art of detecting tramp material



Aug. 10, 4 R. 1... MANEGOLD ET AL 2,446,977

ART CF DETECTING TRAMP MATERIAL Filed Dec. 22, 1945 777 INVENTORS I $420' 5 Q Patented Aug. 1Q, 1948 NEED STATES PATENT OFFICE ART OFDETECTING TRAMP MATERIAL Application December 22, 1945, Serial No.636,870

1 Claim. (Cl. 177-311) Our invention relates generally to improvementsin the art of detecting the presence of tramp material in masses ofprimary material, and relates more particularly to an improved system oflocating dangerous chunks of unduly hard substance accidentallydeposited in bulk materials which are subject to further treatment inmechanisms unadapted to handle the tramp material Without damage.

The principal object of the present invention is to provide an improvedmethod of and instrumentalities for utilizing magnetism to mosteffectively detect the presence of batches of magnetic or non-magnetictramp substances, within a mass of any kind of primary material whichhas previously been handled or treated by equipment from which the trampbatches have broken away or become separated.

In many industries, and especially in the mining industry, masses ofprimary bulk materials such as rock, coal and ore are initially treatedor' handled in equipment such as cars, steam shovels, and crushershaving brake shoes, bucket teeth, liners, or mantles formed of very hardand relatively uncrushable substance, portions of which known as trampbatches break off or become separated from the equipment and fall intothe masses of primary material. When the bulk primary material issubsequently subjected to further treatment such as fine crushing, thetramp batches are liable to cause great damage to the subsequenttreating equipment, so that the hard and uncrushable batches should beeffectively removed before the primary material is further treated. Suchdetection and removal of the tramp or foreign material should preferablybe efiected while the bulk material is advancing or moving from theprimary treating equipment toward the secondary or subsequent treatingequipment.

Many difierent methods of and apparatus for effecting detection andremoval of these batches of tramp substance, have heretofore been proposed and used quite successfully in connection with certain types oftramp material. When this tramp material is magnetic, and the bulk orpri-' mary material is non-magnetic, it is a simple matter to accuratelydetect the presence of the magnetic tramp batches by merely subjectingthem to magnetic influence suflicient to cause the temporarilymagnetized batches to create a detecting electric current in a secondarycoil associated with sensitive signalling mechanism. This cannot howeverbe done when. the tramp batches are composed of non-magnetic materialsuch as manganese steel which is extensively used in the construction ofbrake shoes for cars, teeth for shovel buckets, and liners and mantlesfor crushers. The prior method furthermore cannot be readily utilizedwhen the primary material is composed of more or less magnetic material,such as magnetic ore; and the equipment required in carrying on theprior detection method is also relatively complicated since it requiresthe provision of a complicated primary energizing coil and magnet, whichbesides being relatively intricate and of expensive construction, mustbe constantly electrically energized.

In an effort to obviate the difiiculty of detecting the presence oftramp batches of non-magnetic material such as manganese steel, it hasheretofore been proposed to insert local plugs of magnetic metal in theportions of the initial handling equipment which were most likely tobreak away. When one or more of these plugs was present in a tramp batchand was subsequently subjected to temporary magnetic influence, theywould serve to detect the presence of their carrying batches by settingup detecting electric currents in the secondary coils of the detector orsignalling mechanism; but if no such plugs happen to be present withinthe tramp batches no detection thereof was possible. With this priormethod the plugs which were embedded in the tramp batches were not of apermanently magnetized nature but were only composed of material whichcould be magnetized when subjected to strong electro-magnetic influence;a and we have discovered that by making the plugs of highlymagneticmaterial and by permanently magnetizing the same, the plugs themselveswill create the desired detecting currents in the secondary coils of thedetecting apparatus, without resorting to the use of the primaryelectrically energized and complicated coils heretofore used.-

It is therefore a more specific object of our present inventionto-provide a simple but highly eifective method of detecting thepresence ofbatches of any kind of undesirable tramp material in a massof any kind of primary material, regardless of whether the tramp batchesor the primary material are composed of magnetic or' non-magneticsubstance.

Another specific object of this invention is toprovide an improvedsystem whereby thepr'esence of undesirable batches of tramp materialsuch as manganese steel chunks, in a moving mass of other material suchas ore, rock, or coal, may be quickly and accurately detected andremoved before the' tramp pieces damage subse-i quent equipment fortreating the bulk material.

A further specific object of the invention is to provide simplifiedapparatus for effectively detecting the presence of tramp pieces ofmaterial in a traveling mass f primary material, with the aid ofpermanently magnetized local cores associated with the tramp materialand coacting with a simple detector coil and signal assemblage.

Still another specific object of our invention is to provide an improvedmethod of and apparatus for positively detecting the presence ofnon-magnetic batches of objectionable material within travelling massesof primary bulk materials of various kinds.

These and other specific objects and advantages of the presentimprovement will be appar-- ent from the following detailed description.

A clear conception of the features constituting our present invention,and of the method and apparatusinvolved in commercial exploitationthereof, may be had by referring. to the drawin accompanying and formingapart of this specification wherein like reference characters designatethe same or similar parts in the various views.

Fig. 1 is a perspective view of a typical shovel or dipper tooth such asis ordinarily used on mechanical bulk material handling clippers orshovel buckets, showing one of our improved permanently magnetized coresembedded therein;

Fig. 2- is a fragmentary part sectional side View of a brake shoe andwheel for a car such as customarily utilized for handling coal and orewithdrawn from a mine, also showing several. of our improved permanentlymagnetized detector cores embedded in the shoe liner;

Fig. 3 is a fragmentary central verticalsection through the dischargeportion of a typical gyratory crusher, likewise showing several of ourimproved permanently magnetized' local cores embedded in the head mantleandconcave liner;

Figulis a fragmentary vertical sectioncthrough the outlet of a typicaljaw crusher, again. showing the improved permanently magnetized detectorcores embedded in the discharge ends of. the liners for the fixed andmovable crushing jaws; and

Fig. 5 is a diagrammatic transverse vertical section through a loadedbulk material belt conveyor having a shovel tooth containing one of theimproved permanently magnetized cores embedded inthe primary materialmass, and showing the action of the magnetized core. upon a typicaldetector coil.

While the disclosure in the drawing has been.

limited to only a few typical embodiments or uses of the presentinvention, it is not our desire or intent to unnecessarily restrict theutility of the.

improved method by virtue of this limited showing.

In accordance with our present improved method of detecting the presencein a mass of any kind of bulk primarymaterial, of chunks or batches ofundesirable tramp material which has been accidentally broken orseparated from initial equipment by which the primary material.

has previously been handled or treated; we fixedly associate localpermanentlym agnetized cores with local portions of the equipment whichare subject to relatively frequent breakage and re-' lease of trampbatches into the primary mass, and we subsequently utilize the inherentorpermanent magnetism of the released cores to positively detect thepresence of the tramp. batches with.- in the mass of primary materialThe. primary material may have various characteristics and may be eithermagnetic or non-magnetic, and the same is true of the tramp materialexcept for the local permanently magnetized cores embedded therein,which are referably formed of material such as Alnico which issusceptible of strong and durable permanent magnetization. Thesepermanently magnetimd cores may be embedded within or otherwise rigidlyassociated with the portions of the initial handling equipment, whichare most subject to release of tramp pieces, and the actual detection ofthe presence and location ofl the tramp batches is preferably effectedwhile they are travelling embedded in or reposing on a layer or streamof the primary material travelling fromthe initial equipment towardsubsequent treating equipment such as fine crushers or the like.

Referring to the drawing, Fig. 1 illustrates a typical dipper or shovellbucket tooth 8 having a local permanently magnetized cylindrical core 9of considerable size fixedly embedded therein near its point. Theseteeth 8 are ordinarily formed of wear-resistant non-magnetic metal suchas manganese steel, and rather frequently drop off of their carrierbuckets and mingle with the bulk material which is being handled. Ifpermitted to subsequently enter the crushing zones of various types ofcrushers, these hard teeth 8 may cause considerable damage or stall thecrushing, machines.

In Fig. 2. is shown a typical brake assemblage for cars such as arecustomarily utilized to remove :coal and ore from mines, the assemblycomprising a wheel I0 and a cooperating brake shoe II, the latter beingprovided with a wear-resistant liner I2 having a series of permanentlymagnetized cores 9 fixedly embedded in local portions thereof. The shoeliners l2 may be formed of manganesesteel or other hard butnon-magneticmaterial and chunks [3 are rather frequently broken. therefrom andbecome mixed with the bulk coal or otherprimary material which is beinghandled by the cars.

Fig- 3 is a typical representation of a gyratory crusher such as usedfor initially reducing ore, rock, or the like, and this crushercomprises in general a crushing head l4 carried by a gyratory shaft [5and being protected by a wear-resistant manganese steel mantle I6; and afixed crushing concave I1 protected by a wear-resistant manganese steel.liner l8. which cooperates with the head, mantle I6 to provide anintervening crushing chamber I9. The discharge ends of the mantle. l6andliner I8 are preferably provided with fixedly embedded permanentlymagnetizedcores 9. at local places, that is, wherever chunks l3. ofthese protective elements: are apt to break away and fall into thecrushed primary material.

In Fig. 4 there is shown a typical jaw crusher such as is frequentlyutilized to initially break pit or. minev run rock or coal, and thiscrusher consists primarily of. a movable jaw 20 protected by a manganesesteelor similar wear plate. 21, and a fixed jaw 22.1ikewise. protectedby a suitable: wear plate 23 cooperating'withi the plate 2| toprovide acrushing zone 24. The discharge or outlet portions of the wear plates 2I, 23 of thisjaw' crusher, are likewise provided with fixedly embeddedpermanently magnetized cores 9 at'the local laces where chunks l3 aremoreapt to break off and become mixed with thev product and th plates2lf, 2.3 are usually constructed of non-magnetic hard material such asmanganesesteel or. the like; Now referring specifically to Fig. 5, afterthe primary or bulk material 25 has been initially handled withequipment such as a dipper or shovel, or a car, or a coarse crusher, atthe source of supply, it is usually transported in a continuous streamor a relatively thin layer, to a subsequent treating machine such as afine crusher, with the aid of a conveyor belt 26. In order to detect thepresence of relatively uncrushable pieces 01' tramp batches such as adipper tooth 8 or a chunk 9 of similar material, having one or morepermanently magnetized detector cores 9 embedded therein, we provideonly a detector coil or solenoid 21 comprising a large number of turnsof fine insulated wire wound upon a suitable form of insulated materialand having a laminated magnetic core 28 therein, which is located nearthe path of travel of the conveyor belt 26, preferably with its axisdisposed parallel to the said path. This solenoid 21 may be connected toa sensitive signal or indicating device operable by electric currentinduced in the solenoid by lines of force emanating from a magnetizedcore 9 which is carried within the range of action of the solenoidwindings by the conveyor belt 26, in the usual and well known manner,thus completing the equipment necessary for detection purposes with ourimproved method.

During normal use of the improved apparatus while carrying on our newmethod of detecting, the portions of the equipment which are normallysubject to breakage and release of portions or tramp batches into theprimary material, are provided with permanently magnetized cores ofhighly magnetic material such as Alnico metal, as indicated in Figs. 1to 4 inclusive. When a chunk or batch I 3 of the equipment is thusbroken away and is deposited into the primary material 25 as shown inFig. 5, the permanently magnetized core embedded within the broken awaypiece will constantly radiate or send out lines of flux in alldirections. When no foreign material or tramp batch is contained withinthe primary material 25 which passes th solenoid 21, this solenoidremains inactive; but when a piece of tramp material such as a tooth 8containing a permanently magnetized core 9 comes within range of thesolenoid 21, the flux lines radiating in all directions from themagnetized core will immediately produce electric currents in thesolenoid. The low voltage current thus produced in the solenoid 21 willbe transmitted to the signal apparatus and will thus notify the operatorthat tramp material is contained within the moving mass of material 25in the locality of the solenoid 21. The operator may then remove thedetected tramp material, thus insuring safety in operation for thesubsequent equipment in which the material 25 is to be treated. Sincethe cores 9 are strongly permanently magnetized, th detection will bepositive and accurate, and the signalling device will be operated in amanner which will leave little doubt in the mind of the operator.

From the foregoing detailed description it will be apparent that ourpresent invention provides a simple but highly accurate method ofdetectin tramp batches Within a moving mass of primary material 25, evenif the tramp batches are composed primarily of non-magnetic material.The strongly permanently magnetized cores 9 will afford positiveprotection even if the material 25 is magnetic in character, so that itis immaterial whether the mass of primary material is of a ma netic or anon-magnetic nature. It has been found that a relatively small core ofpermanently magnetized material such as Alnico metal, will positivelyand definitely actuate a solenoid 21 such as heretofore used inconjunction with electrically energized magnets, without necessity ofutilizing such complicated magnet structures, thereby vastly simplifyingthe detecting mechanism, while insuring perfect detection regardless ofthe magnetic or non-magnetic characteristics of the material 25 and ofthe tramp batches.

It should be understood that it is not desired to limit this inventionto the exact steps of the method, or to the precise construction of theapparatus, herein described and shown, for various modifications withinthe scope of the appended claim may occur to persons skilled in the art.

We claim:

The method of detecting in a moving mass of magnetic primary materialthe presence of nonmagnetic batches of tramp material accidentallybroken away from equipment which has previously handled the primarymaterial, which method comprises, embedding intensely and permanentlymagnetized local cores in various portions of the equipment which aresubject to breakage and release of non-magnetic tramp batches containingone or more of said cores into the magnetic primary mass, and utilizingthe inherent intense magnetization of said released cores to indicatethe location of and to facilitate removal of the non-magnetic trampbatches from the mass of magnetic primary material while in motion.

ROBERT L. MANEGOLD. IRA H. WYNNE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,975,976 Robinson Oct. 9, 19342,228,293 Wurzbach Jan, 14, 1941 2,283,277 Modine May 19, 1942

